Such a cooling device is disclosed in DE 2 135 677 A. The prior art cooling device is part of a transformer-rectifier device whose rectifier units are oil-cooled. The rectifier units are accommodated in separate rectifier housings, with the coolant or cooling oil being pumped by a pump through a pipeline and then in parallel through the rectifier units. After passing through and after cooling of the rectifier units, the heated coolant or cooling oil is returned to a cooler from where the coolant or cooling oil travels again to the pump. Near the inlet and outlet of each rectifier housing, valves enable a separation of the individual housings from the pipeline.
Components of power electronics that require cooling are often used in the field of drive technology and electrical energy production. Thus, the use of converter modules in the drive technology of vehicles, such as, for example, streetcars, hybrid busses, or trolley busses, that convert DC voltage into AC voltage and vice versa, is known.
In systems for producing electrical energy, such as in wind power plants, these converters are located in a housing module for electrical equipment. This housing module combines all feed lines of a generator up to a grid feed point. In addition, a transformer, a converter, and a cooling device can be combined as a unit in the housing. Such converters or rectifiers have a power transmission of several 1000 kW. Within a base body, at least two modules preferably can comprise fast-switching power semiconductors, for example, IGBTs, and can be made as prefabricated branch pair modules, such as a branch pair valve set. The heat formed as a result of conversion losses is dissipated to one or more cooling elements. Cooling liquid, often made as a water-glycol mixture for reasons of protecting against corrosion and freezing, flows through and around the cooling elements. Typically, a cooling liquid temperature of less than 70 degrees Celsius for the coolant entry should be maintained.
If work is to be performed on parts of this power electronic system for maintenance purposes, large amounts of cooling liquid may have to be removed from the cooling device. In particular, under constricted space conditions in systems such as the nacelle of a wind turbine, it is often hardly possible to set up suitable collection tanks for receiving the cooling liquid. Moreover, the complete removal of the cooling liquid from these systems is time-consuming.